Field of the Invention
The present invention generally relates to a support prop with a sensor for construction or demolition works. It further relates to support props with sensor devices for forming a network therebetween. It yet further relates to a method of monitoring and adjusting a load present on each support prop and the distribution of the loading among the support props.
Description of Related Art
Use of temporary support systems is indispensable during demolition or construction, erection of buildings and engineering structures. During construction stage, for example, temporary support systems built up from props are widely used to provide a support structure for newly formed concrete floors, decks, etc. Before a freshly poured concrete floor or deck has gain sufficient strength to support its own weight and any imposed loading, the weight of the formwork and concrete are transferred to either the floor below or to the ground by a propping system. Temporary support props are also used to support structural components which have not yet been fully connected or secured.
On the other hand, for demolition works that are adopting the mechanical top down approach, for example, temporary propping systems are installed at the inter-floor spaces in between several consecutive floors to distribute, among the propped floors, the gravity load of heavy demolition machinery operating on the top floor among the propped floors.
Owing to the complexity of site and environmental conditions, the exact/actual loading carried by each individual prop in a temporary load supporting system is usually unknown. The actual distribution of the load depends also largely on the initial load that is applied to each prop during installation and initial set up; however, the initial load has never been checked or monitored owing to the lack of suitable instrument or equipment.
At present, there is not any site viable device or system which is cost effective enough to facilitate regular or continuous monitoring of the load on each prop. In most cases, the design of a propping system is based on either rule of thumb or general past experiences. These uncertainties, when combined with other adverse factors, have led to numerous severe and disastrous failures or accidents.
Currently, the load on a prop may only be measured by placing a load cell/weight sensor at one of the distal ends of the prop. The electrical signal from the load cell has to be connected to a process meter to display the magnitude of the load in force units. The load cell and the process meter have to be calibrated together as a combined set before used to take measurements. Once calibrated, the combination cannot be changed among different load cells and process meters. Power cable and signal transmission cable have to be installed between the process meter and the monitoring station. Thus, the cost of measurement and/or monitoring load on props is very high. The use of cables for signal transmission creates a lot of inconvenience at the construction site and may even become safety hazards. These short comings prevent existing techniques to be applied efficiently for massive data gathering and monitoring.
Thus, there is a need to enhance current equipment to improve safety and effectiveness of the monitoring load on props in a propping system. There further exists a need for a new temporary support propping system with prop forces under monitoring, and with overload warning capabilities in the construction industry.